Nasdaq vs. S&P 500: What Each Index Tracks, Updated November 5, 2026

Verified November 5, 2026, at 17:03 UTC.

The Nasdaq Composite tracks thousands of eligible securities listed on the Nasdaq Stock Market, while the S&P 500 tracks 500 leading large U.S. companies selected under a separate set of rules. Both are widely followed stock market indexes, but they measure different slices of the market and can move by different amounts on the same day.

For investors, the distinction matters because the Nasdaq Composite has a stronger technology tilt, while the S&P 500 covers a broader cross-section of major U.S. industries. Neither index is an equal-weighted vote of its members: large companies have an outsized effect on the headline result.

Destaques

• The Nasdaq Composite is based on eligible Nasdaq-listed securities, including domestic and international companies.
• The S&P 500 represents 500 large U.S. companies selected using criteria that include size, liquidity, and financial viability.
• Both use market capitalization weighting, but the S&P 500 adjusts for shares available to the public.
• The Nasdaq Composite and Nasdaq-100 are different indexes; check which one a headline or fund refers to.

What does the Nasdaq Composite track?

The Nasdaq Composite measures the performance of eligible securities listed on the Nasdaq Stock Market. Its thousands of securities include companies of different sizes and from multiple industries, as well as eligible companies based outside the United States. The index is often associated with technology because technology-related companies have a significant presence, but it is not limited to technology stocks.

Listing is central to its design. A company listed on another exchange is not included simply because it is large or influential. The index also excludes certain security types, including exchange-traded funds and preferred stocks. Nasdaq explains the rules in its Composite methodology.

The Composite is market-cap weighted. In practical terms, a larger constituent generally has more influence on the index than a smaller one. So even though the index contains thousands of securities, a small group of very large companies can drive much of its movement. Nasdaq describes this weighting in its comparison of its two major indexes.

What does the S&P 500 track?

The S&P 500 measures the large-cap segment of the U.S. stock market through 500 constituent companies. It is designed to reflect leading businesses across major industries, making it a commonly used benchmark for U.S. large-company stocks. Unlike the Nasdaq Composite, its membership is not restricted to one exchange.

Companies must meet eligibility requirements involving factors such as market value, trading liquidity, public float, and financial viability. An index committee selects among eligible companies and considers sector representation; inclusion is not simply an automatic list of the 500 largest stocks. The provider explains the approach in its S&P 500 overview.

The S&P 500 is weighted by float-adjusted market capitalization. Market capitalization is a company’s share price multiplied by its shares outstanding; float adjustment accounts for shares available to public investors. A company with a larger float-adjusted market value generally has a greater effect on the index. Having 500 companies therefore does not mean each contributes one five-hundredth of the daily move.

What is the difference between the Nasdaq and the S&P 500?

The most useful distinction is what determines membership. The Nasdaq Composite starts with eligible securities on a particular exchange. The S&P 500 starts with eligible large U.S. companies and selects a group intended to represent major industries. Some companies appear in both, so the indexes are not independent alternatives.

• Coverage: The Composite includes thousands of eligible securities, including international listings; the S&P 500 includes 500 large U.S. companies.
• Industry mix: Both span multiple industries, but the Composite has a pronounced technology tilt. The S&P 500 seeks broader representation of major U.S. industries.
• Weighting: Both give larger companies more influence. The Composite uses market capitalization; the S&P 500 uses float-adjusted market capitalization.
• Selection: The Composite relies heavily on listing and security eligibility. The S&P 500 applies additional company-level criteria and committee selection.

A higher number of holdings does not automatically mean the Composite is more diversified in every respect. Concentration by company, industry, and geography also matters. Conversely, the S&P 500 is broad among large U.S. companies but does not represent every small company or the entire global market.

Why can the Nasdaq and S&P 500 move differently?

The indexes hold different securities and assign different weights to shared companies. If large technology-related stocks rise sharply, the Composite may gain more because of its exposure. If another group of industries performs better, the S&P 500 may hold up better. These are conditional examples, not reliable predictions: actual results depend on which stocks move and their weights at the time.

Compare percentage changes, not point changes, when judging their daily performance. The indexes have different starting levels and calculation histories, so a 100-point move in one is not directly comparable with a 100-point move in the other. Also check whether a quoted return includes dividends: a price index and a total-return index answer different questions.

Is the Nasdaq-100 the same as the Nasdaq Composite?

No. The Nasdaq-100 is a separate index designed to measure 100 of the largest Nasdaq-listed nonfinancial companies. It uses a modified market-capitalization weighting method and has a much narrower membership than the Composite. The Nasdaq-100 methodology sets out its eligibility and weighting rules.

When a report says “the Nasdaq,” look for the full index name or ticker. The distinction is especially useful when comparing a fund’s results with a news headline: a fund tracking the Nasdaq-100 is not designed to match the Nasdaq Composite.

Can you invest in the Nasdaq or S&P 500?

You cannot buy an index directly, but mutual funds and exchange-traded funds may seek to track one. Before choosing a fund, check its named benchmark, holdings, expense ratio, and tracking record. Fund returns can differ from index returns because of expenses and the way the fund replicates the index. The SEC’s Investor.gov guide to index funds explains these costs and risks.

Owning funds that track both indexes can increase exposure to overlapping large companies rather than add as much diversification as their different names suggest. The right comparison depends on the rest of a portfolio, the investor’s time horizon, and tolerance for losses. Index funds can lose value, and past performance does not guarantee future results.

FAQ

Is the Nasdaq Composite only technology stocks?

No. It includes eligible Nasdaq-listed securities from multiple industries, although technology-related companies have a significant influence.

Does the S&P 500 include Nasdaq-listed companies?

Yes. Eligible Nasdaq-listed companies can be selected for the S&P 500, so some companies appear in both indexes.

Which index is better for tracking the overall U.S. market?

The S&P 500 is a common benchmark for large U.S. companies across major industries. For a fuller picture that includes smaller U.S. companies, consider a broader total-market benchmark as well.